A view through a construction fence shows the Kremlin towers and St. Basil's Cathedral on a hot summer day in central Moscow, Russia, July 1, 2016. REUTERS/Maxim Zmeyev

Democratic U.S. lawmakers accused Russia on Wednesday of a “relentless assault” on democratic institutions worldwide, and called on President Donald Trump to treat election interference as a national crisis.

Democrats on the Senate Foreign Relations Committee released a report detailing what they described as nearly two decades of Russian efforts to tilt politics across Europe, criticizing Trump for doing too little to address the issue.

The report was commissioned by Senator Ben Cardin, the committee’s top Democrat, who said on Wednesday that President Vladimir Putin would “push as far as he’s allowed to push, if we don’t push back.”

Kremlin spokesman Dmitry Peskov, who has repeatedly denied accusations by U.S. intelligence officials and others that Moscow interferes in any foreign elections, told a conference call with reporters Russia rejected any accusations of meddling and was dismayed to see such allegations still being made.

“With regards to this (anti-Russian) campaign, all we can do is express our regret and repeat that these accusations remain unfounded,” said Peskov.